Running multiple servers on one system
Running multiple PostgreSQL servers on one physical system is possible if it is convenient for your needs.
Getting ready
Once again, make sure you've read the Deciding on a design for multitenancy recipe so that you're certain this is the route you wish to take. Other options exist, and they may be preferable in some cases.
How to do it…
Core PostgreSQL easily allows multiple servers to run on the same system, but there are a few wrinkles to be aware of.
Some installer versions create a PostgreSQL data directory named data. It then gets a little difficult to have more than one data directory without using different directory structures and names.
Debian/Ubuntu packagers chose a layout specifically designed to allow multiple servers, potentially running with different software release levels. You might remember this from the Locating the database server files recipe in Chapter 2, Exploring the Database.
Starting from /var/lib/postgresql, which is the home directory...
